"An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force."

Objects tend to "keep on doing what they're doing." In fact, it is the natural tendency of objects to resist changes in their state of motion. This tendency to resist changes in their state of motion is described as inertia.

so, Inertia: the resistance an object has to a change in its state of motion.

ACTIVITY FOR STUDENTs~

1.

When the cardboard is jerked quickly, the coin will fallinto the glass.

The inertia of the coin resists the change of its initial state, which is stationary.

As a result, the coin does not move with the cardboard and falls into the glass because of gravity.

2.

When the book is pulled out, the books on top will fall downwards.

Inertia tries to oppose the change to the stationary situation, that is, when the book is pulled out, the books on top do not follow suit.

So, sekarang cikgu nak kaitkan antara MASS dan INERTIA~

WHAT IS MASS?

Mass is defined as the amount of matter. The SI unit of mass is kilogram (kg)
Mass is a scalar quantity.

Inertia is the property of a body that tends to maintain its state of motion.

the relationship is,

Object with more mass offers a greater resistance to change from its state of motion.
Object with larger mass has larger inertia to resist the attempt to change the state of motion.